Is there a way to upgrade from Cubase 5 to Cubase 7?
The reason being a project created in 7, transferred to a computer using 5 and needing to be returned to original 7 computer.
I see there is a download on the website for Cubase 7 that needs a licence to operate.
Is it possible for Steinberg to sell the Cubase 5 user the Cubase 7 licence?
Thanks in advance for any helpful replies.
Steinberg (on the webshop site run by asknet) only sells the latest version of their software. You might look into purchasing the latest version which will open the CB7 project.
Another option would be to find/purchased a previously owned CB 7. Buyer beware though.
Regards 
A Cubase Pro 9.5 license can run Cubase 7, but Cubase 9.5 can also open Cubase 7 projects without issues.
Since Cubase 9.5 now only supports 64 bit VST FX / Instruments, there can be issues opening Cubase 7 Projects, if 32 bit VST Fx / Instruments were used.